氯化甲基汞对大鼠海马c-jun蛋白表达的影响

 为了探讨氯化甲基汞(MMC)对大鼠海马损伤的分子机制,应用免疫组织化学方法观察了氯化甲基汞对大鼠海马JUN蛋白表达的影响(对照组为0.9%生理盐水、暴露组浓度分别为0.05,0.5,5mg/kg;取样时间分别为20,60,240,1440min).结果发现,暴露组大鼠海马JUN蛋白表达均高于对照组,氯化甲基汞对大鼠海马JUN蛋白表达与其浓度之间有一定的剂量反应关系,表明即刻早期基因(c-jun)参与了氯化甲基汞对海马损害的毒性过程.  

亚慢性全氟辛烷磺酸染毒对大鼠海马细胞钙稳态的影响

 采用经口摄食染毒,探讨全氟辛烷磺酸(PFOS)对大鼠血清与脑组织中PFOS浓度及海马细胞内钙离子浓度([Ca2+]i)的影响,观察大鼠大脑皮质、海马和小脑组织病理学变化.结果表明,染毒组大鼠血清与脑组织中PFOS浓度、海马细胞内[Ca2+]i均显著高于对照组,且随着染毒剂量的升高,海马细胞内[Ca2+]i升高.大鼠血清与脑组织中PFOS浓度、脑组织中PFOS浓度与海马细胞[Ca2+]i均呈现显著的正相关关系.染毒组大鼠大脑皮质、海马和小脑组织中未见尼氏体染色变浅等病理性改变.  

汞污染粮食诱导大鼠海马c-FOS蛋白表达

为了探讨我国典型汞污染地区汞污染生物效应 ,并尝试应用即刻早期基因c-fos表达变化早期预报典型汞污染地区汞神经毒性的可行性 ,本文应用免疫组织化学方法研究了实验粮食饲喂后 ,大鼠海马c-FOS蛋白表达变化 .结果表明污染粮食显著诱导大鼠海马c-FOS蛋白表达 ;在饲喂过程中硒与汞有拮抗效应 .初步推断 ,即刻早期基因c-fos表达变化可以作为汞污染地区汞神经毒性检测和评价效应指标 .  

Neurobiology of the homing pigeon—a review

Homing pigeons are well known as good homers, and the knowledge of principal parameters determining their homing behaviour and the neurological basis for this have been elucidated in the last decades. Several orientation mechanisms and parameters—sun compass, earth’s magnetic field, olfactory cues, visual cues—are known to be involved in homing behaviour, whereas there are still controversial discussions about their detailed function and their importance. This paper attempts to review and summarise the present knowledge about pigeon homing by describing the known orientation mechanisms and factors, including their pros and cons. Additionally, behavioural features like motivation, experience, and track preferences are discussed. All behaviour has its origin in the brain and the neuronal basis of homing and the neuroanatomical particularities of homing pigeons are a main topic of this review. Homing pigeons have larger brains in comparison to other non-homing pigeon breeds and particularly show increased size of the hippocampus. This underlines our hypothesis that there is a relationship between hippocampus size and spatial ability. The role of the hippocampus in homing and its plasticity in response to navigational experience are discussed in support of this hypothesis.  

Fractionating dead reckoning: role of the compass, odometer, logbook, and home base establishment in spatial orientation

Rats use multiple sources of information to maintain spatial orientation. Although previous work has focused on rats’ use of environmental cues, a growing number of studies have demonstrated that rats also use self-movement cues to organize navigation. This review examines the extent that kinematic analysis of naturally occurring behavior has provided insight into processes that mediate dead-reckoning-based navigation. This work supports a role for separate systems in processing self-movement cues that converge on the hippocampus. The compass system is involved in deriving directional information from self-movement cues; whereas, the odometer system is involved in deriving distance information from self-movement cues. The hippocampus functions similar to a logbook in that outward path unique information from the compass and odometer is used to derive the direction and distance of a path to the point at which movement was initiated. Finally, home base establishment may function to reset this system after each excursion and anchor environmental cues to self-movement cues. The combination of natural behaviors and kinematic analysis has proven to be a robust paradigm to investigate the neural basis of spatial orientation.